1. Field of the Invention
The present invention relates to a working apparatus such as a one-surface grinding apparatus which is used to work the back surface of a wafer with an IC (Integrated Circuit), an edge grinding apparatus for working the edge of a circular-shaped thin plate and a machining center for performing many kinds of workings with many kinds of working tools.
2. Description of the Related Art
For example, in producing an IC tip, after an IC (Integrated Circuit) is produced on one surface of a mirror-surface silicone wafer, as a wafer""s back surface working operation, a grinding operation is executed on the other surface of the silicone wafer. In this case, firstly, one surface, namely, the back surface of the silicone wafer is roughly cut using a rough grindstone. After completion of the rough cutting operation, the thus rough cut surface is ground using a finishing grindstone to thereby carry out a finishing treatment on the same.
Also, in grinding a circular-shaped thin plate such as a semiconductor wafer, surface grinding is firstly executed. After completion of the surface grinding, the outer peripheral edge of the semiconductor wafer is ground. Conventionally, as such wafer edge grinding, only the rough grinding is executed; but, recently, for the wafer edge grinding as well, there has been requested finishing grounding. Therefore, in the wafer edge grinding operation as well, the wafer edge is firstly ground roughly and, after then, finish grounding is executed on the roughly ground edge of the wafer.
When one surface of the wafer is ground, conventionally, there is used a one surface grinding apparatus which uses, for example, two spindles. In this one surface grinding apparatus, a rough grindstone is mounted on one of the two spindles, while a finishing grindstone is mounted on the other. And, the wafer is roughly ground using the rough grindstone mounted on one spindle and, after then, the wafer is moved to the position of the other spindle and is then finish ground using the finishing grindstone.
And, there is also used a one surface grinding apparatus which uses a spindle. In the case of this one surface grinding apparatus, a grindstone is mounted onto the spindle by a bolt and is then used to grind one surface of a work. More specifically, in this grinding apparatus, when the roughness of the grindstone must be changed as a grinding process progresses, for example, an operator unbolts the bolt to thereby remove the grindstone by hand and, next, the operator mounts a new grindstone onto the spindle.
However, of the above-mentioned two conventional one surface grinding apparatus, in the case of the one surface grinding apparatus using two spindles, because two spindles are necessary, the whole one surface grinding apparatus is complicated in structure and large in size. Also, there is further necessary a delivery device which is used to deliver a work between the two spindles.
On the other hand, in the case of the one surface grinding apparatus using a spindle, it is necessary to replace the grindstone each time the grinding process progresses. This raises a problem that the operator has to take much time and labor. Also, because the grindstone must be manually replaced by the operator, it takes long time to complete the whole grinding operation.
In order to solve the above problems, for example, there is known a one surface grinding machine which is disclosed in JP-A-1-257555. This one surface grinding machine comprises a plurality of cup-type grindstones disposed concentrically with one another and differing in diameter and kind from one another, and drive means for driving these cup-type grindstones individually. And, the plurality of cup-type grindstones are capable of executing grinding operations ranging from a rough grinding operation up to a finish grinding operation on a work in accordance with the feeding movements of the work. In the case of this one surface grinding machine, the whole apparatus (that is, the whole of the one surface grinding machine) can be made compact.
However, in the one surface grinding machine disclosed in the above-cited publication, in case where the grindstone is worn and degraded, an operator replaces the degraded grindstone with a new grindstone by hand. Therefore, not only it takes time and labor to grind the work, but also it takes time to execute the grindstone replacing operation. This drawback is also caused in the conventional edge grinding machine as well.
The present invention aims at eliminating the above drawbacks found in the conventional working apparatus. Accordingly, it is an object of the invention to provide a working apparatus which is simple in structure and small in size, does not cost an operator enormous labor, and is capable of executing a grinding operation in a short time.
In attaining the above object, there is provided a working apparatus for working a work, including: a spindle fixedly mounted with a first working tool for working the work in a specific manner. The spindle is formed with a tool mounting portion mountable onto a second working tool.
Accordingly, in a spindle onto which a grinding tool can be mounted, there is formed a tool mounting portion such as a grindstone mounting portion; and, a grinding tool such as a grindstone to be mounted into the tool mounting portion can be replaced using an automatic tool replacement device. Thanks to this, a single spindle can be used and, when compared with a structure using two spindles, the whole one surface grinding apparatus can be reduced in size.
Also, an operation to replace a worn grinding tool can be facilitated, an operator can be set free from enormous time and labor necessary for the grinding tool replacing operation, and the grinding operation can be executed in a short time. Further, since the grinding operation can be carried out while replacing a grindstone with a second grindstone having different roughness, the grinding operation can be carried out with high efficiency as a whole.